Introduction: nature of the problem

Total knee arthroplasty (TKA) is an effective, reliable, and durable treatment of end-stage symptomatic arthritis of the knee. However, with conventional polyethylene, mechanical failure consisting of wear, osteolysis, and loosening are the primary source for failure in active patients and at long-term follow-up following some modular TKA systems. Other designs have not shown the same rate of loosening, although osteolysis remains a concern. Newer designs with conventional polyethylene have not yet shown significant wear and osteolysis at early follow-up, but long-term studies do not exist.

The successful introduction of a highly cross-linked polyethylene into total joint arthroplasty began in the hip as a response to excessive wear and osteolysis noted with conventional polyethylene stored in air. Short-term clinical studies by Hodrick and colleagues and Minoda and colleagues recently showed successful outcomes with highly cross-linked polyethylene in a posterior cruciate–retaining TKA design.

This is the first clinical study to examine outcomes with highly cross-linked polyethylene applied to a posterior stabilized design. The polyethylene post provides a further area for concern with the altered mechanical properties of highly cross-linked polyethylene. We sought to determine whether this new substance affects the short-term outcomes of posterior stabilized TKA, and specifically to address the concerns of tibial post failure.